Re: correcting Emacs CHAR_COMPONENTS_VALID_P

[Kenichi Handa <handa@etl.go.jp>]

Dave Love <d.love@dl.ac.uk> writes:
> You wrote: 
>>  Dave Love <d.love@dl.ac.uk> writes:
>>  
>>  > I accidentally made a bogus character from a 94x94 charset like
>>  >   (make-char 'japanese-jisx0208 32 32)
>>  
>>  > and was confused by the result of inserting it.
>>  
>>  > Is it worth fixing, or is it intentional for efficiency or something?
>>  > It isn't trivial to fix because several functions and macros are
>>  > affected.
>>  
>>  The current behaviour is intentional.  Efficiency is one
>>  reason.  Another reason is historical one.  There exists
>>  many files that contains invalid byte sequences such as 0xA0
>>  0xA0 (especially EUC-GB).  Before we introduce
>>  eight-bit-control and eight-bit-graphic, we couldn't decode
>>  them properly if we treat them as invalid byte sequence.
>>  Thus I made the rule loosen.  Now, as we have
>>  eight-bit-graphic, we can make the rule firm, but I think
>>  it's not worth spending time on it.

> I think that deserves commentary in the sources to avoid anyone else
> wasting time looking at it.

I agree, and thank you for pointing out that.  Would you
please add a proper comment to the source?  I still can't
contribute any code for the current version of Emacs.  :-(

---
Ken'ichi HANDA
handa@etl.go.jp